Just caught this in the evening news:
Essentially a town in long island, NY is going to allow some residents to build windmills in their back yards. The windmills will cost about $20,000.
My question is: can these wind mills really generate enough power to reliably cover the energy needs of a typical upscale home? How long before one could make up it’s purchase cost?
Given that it’s sometimes going to be calm for extended periods, this would certainly require serious energy storage (e.g. many large batteries). A better way is an arrangement whereby the peak output is more than what’s needed, so it’s fed into the electrical grid and you receive credit against your usage at other times.
Various Googling suggests the average US household uses around 11000 kwh annually (presumably an “upscale” home would use a bit more). The video with the OP link seems to imply windmills around 12 to 15 feet in diameter. The graph near the top of this web page suggests such a windmill would need a fairly impressive average wind velocity to produce that much energy in a year.
I’ll just note that a single human who consumes food, in a well-insulated room is enough to warm it several degrees. That single human can also singlehandedly cut down wood for a fire, use a hand pump to bring water out of the ground, and write stories or create games to amuse himself.
So I mean really, for somebody even not having a windmill they’ll still be meeting their power requirements.
But whether a $20,000 windmill will produce enough energy to offset it’s own pricetag before breaking down–I would guess that the answer is “unlikely.” Nor would I be surprised if the amount of power that goes into creating the components of the windmill takes more energy than the windmill ever produces. That would be a fun question to answer.
The energy payback for a wind turbine is 2-3 years, just like PV: http://www.biofuels.coop/windblog/?p=13
In areas with a good wind resource, turbines can be more cost-effective than grid electricity. I’m not sure Long Island qualifies, but that’s a different issue.
Actually, your link says 2-3 years for PV, but 2-3 month for windmills.
On the other hand, there’s a comment at the bottom there by Thomas L. Wayburn, that
and with a link to his own website.
(I have no idea what the right answer is, or whether his calculations are valid. He claims to have a Ph.D. in chemical engineering, FWIW.)
This is why I don’t like embodied energy calculations. It’s usually much easier to just do the calculations based on ROI, and assume that money is proportional to energy.
In other words, if it took 100GWh to make a turbine, it would be too expensive to buy.
This has the added advantage that you don’t have to convince people to care about the environment in order to convince them to do environmentally sound things. It’s a lot easier to sell someone a windmill because “you’ll save money” than it is to sell them one because “you’ll save the Earth”.
How noisy is one windmill (for one house)?
If this is a dumb question, substitute a smart one and answer ir. 
A better question might be how large would a windmill have to be in order to power a house. I researched it a few years ago and found blades 12 feet long would be required. If each blade is 12 feet long the total diameter of the essential apparatus would be about 25 feet. Add to this the distance above the ground at which it would have to be placed and you’d run into insurmountable problems with your local zoning regulations. Heck, in my town you can’t build a fence over 8 feet high.
Full steam ahead if you own a ranch or farm, though.
I’ve long yearned for a windmill, but I guess it’s not in the cards.
Thanks, though.
There is a neighbor who has a little (d=3’) windmill on his roof connected to a battery bank (assembled from junkyard stuff). He uses it as emergency power (very unreliable service in his area). It powers all the essentials indefinitely.
Then again, power consumption is the key here. I consider him a very frugal man in matters of power. My peak consumption is 500 KWh a month (and I make a scene when I get a bill like that). 11 MWh a year? WTH? Those little levers on the walls are called switches, people.
Going off grid is not a matter of technology, but of philosophy. You must cut consumption before going that route.